[Effects of age on blood pressure, heart rate, and sensory blockade by spinal anesthesia with plain 0.5% bupivacaine].

To discover the influence of age on spinal blockade with plain bupivacaine, 23 patients were administered a subarachnoid injection of approximately 4.0 ml of 0.5% bupivacaine. The patients were divided into two groups. One group consists of patients with ages under 65 years (younger group, n = 13), and the other group consists of patients older than 65 years (elder group, n = 10). The following results were obtained. The time to onset of anesthetic effects (pinprick discrimination, temperature discrimination, and light touch discrimination) decreased with age. At 180 min after the administration, spinal blockade level did not have a significant difference. The degree of the decrease of systolic arterial pressure was greater in the elder group than in the younger group. However, the degree of the decrease of heart rate was greater in the elder group than in the younger group.